• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Luxman SQ-N150 Review (Tube Amplifier)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 218 76.5%
  • 2. Not terrible (postman panther)

    Votes: 47 16.5%
  • 3. Fine (happy panther)

    Votes: 8 2.8%
  • 4. Great (golfing panther)

    Votes: 12 4.2%

  • Total voters
    285

pablolie

Senior Member
Forum Donor
Joined
Jul 8, 2021
Messages
459
Likes
724
Location
bay area, ca
Do any of their models feature a "Dial-a-THD" knob?:facepalm:
Nor do I know nor do I care. Luxman is there and they have a loyal (and seemingly affluent) customer base it seems. I have clearly stated they are not my pick these days. But remember they were GONE ... then came back to life and probably researched their market niche, seemingly well, because they are still around.
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,638
Location
Santa Fe, NM
Not sure I agree. Tell me of another tube amp in the 10W game that measures better. :) This is clearly designed for a narrow audience. Many tube designs are fake tube designs that kinda keep tubes in the preamp section but really amp stuff up in solid state. It's cheaper and makes it easier to pass homologation.
My 2A3 single ended triode amplifier does way better than the Luxman reviewed here. The THD is something like 0.03%.
 

Ken Tajalli

Addicted to Fun and Learning
Forum Donor
Joined
Sep 8, 2021
Messages
554
Likes
281
Location
London UK
Problem is not preference, it's that within the design paradigm, this is implemented poorly.
I said that a while ago, people disagreed with me.

1655941845342.png


I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
12,777
Likes
12,578
Location
Canada
I said that a while ago, people disagreed with me.

View attachment 214151

I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?
Perhaps sending the unit back to Luxman for warranty service would prove that to be true. Have them service it and then get it tested by @amirm a second time.
 

MAB

Active Member
Forum Donor
Joined
Nov 15, 2021
Messages
257
Likes
429
Location
Portland, OR, USA
Not sure I agree. Tell me of another tube amp in the 10W game that measures better. :)
This was demonstrated early in this thread. The example was a classic that a Luxman of that era should have competed against. The old Dynaco smoked this modern Luxman.
Just for giggles, I put my Dynaco SCA-35 power amp section which I built into the chassis below on my bench. This amplifier uses the same output tubes as the Luxman and can do 17 watts per channel. I set up my 'dashboard' and the results are below. This half-century-old Dynaco beats the Luxman at the same measurement conditions. The THD is 0.08145% and the THD+N is 0.11096% - easily beating the far more expensive Luxman. You can see that there is still a strong 2nd order harmonic distortion present in this amp where ideally there should be very little, but it still beats the Luxman.

Fail for team Luxman. :facepalm:

View attachment 212899


View attachment 212900
 

pablolie

Senior Member
Forum Donor
Joined
Jul 8, 2021
Messages
459
Likes
724
Location
bay area, ca
I said that a while ago, people disagreed with me.

View attachment 214151

I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?
Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?
 

pablolie

Senior Member
Forum Donor
Joined
Jul 8, 2021
Messages
459
Likes
724
Location
bay area, ca
This was demonstrated early in this thread. The example was a classic that a Luxman of that era should have competed against. The old Dynaco smoked this modern Luxman.
And I replied. The old Dynaco would not pass any homologation test these days, IMO (I did omit the product name to not offend anyone). Plus, seriously, if that is the perfect measurement chart and you're setting that as a standard... remind me if Amir recommended it? :) you know that's just being biased. :-D
 

pseudoid

Major Contributor
Forum Donor
Joined
Mar 23, 2021
Messages
1,680
Likes
985
Nor do I know nor do I care.
You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.:cool:
 

pablolie

Senior Member
Forum Donor
Joined
Jul 8, 2021
Messages
459
Likes
724
Location
bay area, ca
You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.:cool:
I hope you know I am not in opposition of your point.
 

MAB

Active Member
Forum Donor
Joined
Nov 15, 2021
Messages
257
Likes
429
Location
Portland, OR, USA
And I replied. The old Dynaco would not pass any homologation test these days, IMO (I did omit the product name to not offend anyone). Plus, seriously, if that is the perfect measurement chart and you're setting that as a standard... remind me if Amir recommended it? :) you know that's just being biased. :-D
So... There is something unique about that Dynaco that gave it an unfair advantage? What uniquely prevents it from 'homologation'? And that disqualifies the measurements? (I wanna say tube-PEDs;)) On a technicality like this? It just shows really how poor this amp is. It is not alone, lots of these things have cropped up, and Luxman is one of the brands that is filling the vacuum. Too bad, I am a big fan of vintage Luxman, and I have several old school Luxman pieces I prize, and this is none of that...
Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?
Perhaps this is easy to confuse. The harmonic distortion this unit demonstrates is not the euphonic type people want. It is the power supply ringing the output stage. That distortion shows up as even harmonics (because of the nature of the tubes), but the source is not the music but rather the power supply.

The Dynaco has none of this, just the even harmonics intrinsic to this tube implementation. The Dynaco is properly designed to minimize these issues that the Luxman has.
 

levimax

Major Contributor
Joined
Dec 28, 2018
Messages
1,435
Likes
2,054
Location
San Diego
You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.:cool:
According to this review a stock Mc275 has far less distortion than the Luxman https://www.stereophile.com/content/mcintosh-mc275-power-amplifier-measurements
 

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
5,479
Likes
16,026
Location
Mid-Atlantic, USA. (Maryland)

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,638
Location
Santa Fe, NM
Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?
Unfortunately high 2nd harmonics is the point of many amplifiers made today, but that is not how it should be nor has to be. Imagine that every record you purchased (if you purchased records) had mixed in the sound of severe ticks and pops that you couldn't defeat so that it 'sounds like a record'. Amplifiers with intentionally high distortion are just as silly.

And note that this is not only happens with tubes, but solid state amplifiers as well - even hyper expensive ones. Just look at the measurements and graphs of the distortion of this monstrosity.

The point is that amplifiers like the Luxman and others which intentionally have high distortion in order to pander to the perceived market of today should be firmly called out in places like ASR. Somebody has to call out intentionally defective designs like this as a dumbing-down of the goals of High Fidelity.

Being on this site, I assume that you're interested in something resembling the best and truest reproduction you pay your money for. If ASR can call attention to purposefully hobbled designs so that people seeking advise on their purchases can avoid them, so much the better.
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,638
Location
Santa Fe, NM
That was back when they were trying to minimize distortion, not turn it into a selling point.

Here are a couple of ads from the day. Focus seems to be on fidelity, not a pleasing distortion profile.

View attachment 214155

View attachment 214154
I don't know off hand what the distortion in a test with the same operating levels the Mac has, but I am certain it is nowhere near 0.4% like the Luxman.
 

SIY

Master Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
8,498
Likes
19,168
Location
Alfred, NY
Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?
In ad copy or for real? You do understand that properly adjusted push pull tube amps have very low second?
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,638
Location
Santa Fe, NM
Non-matched output tubes is still the most likely.
The tubes are fine. Its the designer tube sockets which are not matched. :oops:
 
  • Like
Reactions: SIY

Pirx

Member
Joined
Mar 16, 2020
Messages
13
Likes
20
Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?
The 2nd harmonic should not dominate in properly designed Push-Pull construction.
This is kind of operation where the 2nd harmonic from both EL84 should cancel in output transformer and we should see the 3rd dominating, but ofc much, much lower than this Luxman.
That amplifier should not represent "tube world" in any case but the look.
 
Top Bottom